// SetCharmURL sets the charm URL for each given unit. An error will
// be returned if a unit is dead, or the charm URL is not know.
func (u *UniterAPI) SetCharmURL(args params.EntitiesCharmURL) (params.ErrorResults, error) {
	result := params.ErrorResults{
		Results: make([]params.ErrorResult, len(args.Entities)),
	}
	canAccess, err := u.accessUnit()
	if err != nil {
		return params.ErrorResults{}, err
	}
	for i, entity := range args.Entities {
		err := common.ErrPerm
		if canAccess(entity.Tag) {
			var unit *state.Unit
			unit, err = u.getUnit(entity.Tag)
			if err == nil {
				var curl *charm.URL
				curl, err = charm.ParseURL(entity.CharmURL)
				if err == nil {
					err = unit.SetCharmURL(curl)
				}
			}
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}

// GetPrincipal returns the result of calling PrincipalName() and
// converting it to a tag, on each given unit.
func (u *UniterAPI) GetPrincipal(args params.Entities) (params.StringBoolResults, error) {
	result := params.StringBoolResults{
		Results: make([]params.StringBoolResult, len(args.Entities)),
	}
	canAccess, err := u.accessUnit()
	if err != nil {
		return params.StringBoolResults{}, err
	}
	for i, entity := range args.Entities {
		err := common.ErrPerm
		if canAccess(entity.Tag) {
			var unit *state.Unit
			unit, err = u.getUnit(entity.Tag)
			if err == nil {
				principal, ok := unit.PrincipalName()
				if principal != "" {
					result.Results[i].Result = names.UnitTag(principal)
				}
				result.Results[i].Ok = ok
			}
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}

// ConfigSettings returns the complete set of service charm config
// settings available to each given unit.
func (u *UniterAPI) ConfigSettings(args params.Entities) (params.ConfigSettingsResults, error) {
	result := params.ConfigSettingsResults{
		Results: make([]params.ConfigSettingsResult, len(args.Entities)),
	}
	canAccess, err := u.accessUnit()
	if err != nil {
		return params.ConfigSettingsResults{}, err
	}
	for i, entity := range args.Entities {
		err := common.ErrPerm
		if canAccess(entity.Tag) {
			var unit *state.Unit
			unit, err = u.getUnit(entity.Tag)
			if err == nil {
				var settings charm.Settings
				settings, err = unit.ConfigSettings()
				if err == nil {
					result.Results[i].Settings = params.ConfigSettings(settings)
				}
			}
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}

func (s *UnitSuite) newAgent(c *gc.C, unit *state.Unit) *UnitAgent {
	a := &UnitAgent{}
	s.initAgent(c, a, "--unit-name", unit.Name())
	err := a.ReadConfig(unit.Tag())
	c.Assert(err, gc.IsNil)
	return a
}

func waitForUnitStarted(stateConn *state.State, unit *state.Unit, c *gc.C) {
	timeout := time.After(5 * time.Second)

	for {
		select {
		case <-timeout:
			c.Fatalf("no activity detected")
		case <-time.After(coretesting.ShortWait):
			err := unit.Refresh()
			c.Assert(err, gc.IsNil)
			st, info, data, err := unit.Status()
			c.Assert(err, gc.IsNil)
			switch st {
			case params.StatusPending, params.StatusInstalled:
				c.Logf("waiting...")
				continue
			case params.StatusStarted:
				c.Logf("started!")
				return
			case params.StatusDown:
				stateConn.StartSync()
				c.Logf("unit is still down")
			default:
				c.Fatalf("unexpected status %s %s %v", st, info, data)
			}
		}
	}
}

// PublicAddress returns the public address for each given unit, if set.
func (u *UniterAPI) PublicAddress(args params.Entities) (params.StringResults, error) {
	result := params.StringResults{
		Results: make([]params.StringResult, len(args.Entities)),
	}
	canAccess, err := u.accessUnit()
	if err != nil {
		return params.StringResults{}, err
	}
	for i, entity := range args.Entities {
		err := common.ErrPerm
		if canAccess(entity.Tag) {
			var unit *state.Unit
			unit, err = u.getUnit(entity.Tag)
			if err == nil {
				address, ok := unit.PublicAddress()
				if ok {
					result.Results[i].Result = address
				} else {
					err = common.NoAddressSetError(entity.Tag, "public")
				}
			}
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}

func (s *MachineSuite) waitProvisioned(c *gc.C, unit *state.Unit) (*state.Machine, instance.Id) {
	c.Logf("waiting for unit %q to be provisioned", unit)
	machineId, err := unit.AssignedMachineId()
	c.Assert(err, gc.IsNil)
	m, err := s.State.Machine(machineId)
	c.Assert(err, gc.IsNil)
	w := m.Watch()
	defer w.Stop()
	timeout := time.After(coretesting.LongWait)
	for {
		select {
		case <-timeout:
			c.Fatalf("timed out waiting for provisioning")
		case _, ok := <-w.Changes():
			c.Assert(ok, jc.IsTrue)
			err := m.Refresh()
			c.Assert(err, gc.IsNil)
			if instId, err := m.InstanceId(); err == nil {
				c.Logf("unit provisioned with instance %s", instId)
				return m, instId
			} else {
				c.Check(err, jc.Satisfies, state.IsNotProvisionedError)
			}
		}
	}
	panic("watcher died")
}

func (s *FilterSuite) APILogin(c *gc.C, unit *state.Unit) {
	password, err := utils.RandomPassword()
	c.Assert(err, gc.IsNil)
	err = unit.SetPassword(password)
	c.Assert(err, gc.IsNil)
	s.st = s.OpenAPIAs(c, unit.Tag(), password)
	s.uniter = s.st.Uniter()
	c.Assert(s.uniter, gc.NotNil)
}

func (s *ConnSuite) assertAssignedMachineRequestedNetworks(c *gc.C, unit *state.Unit, expectInclude, expectExclude []string) {
	machineId, err := unit.AssignedMachineId()
	c.Assert(err, gc.IsNil)
	machine, err := s.conn.State.Machine(machineId)
	c.Assert(err, gc.IsNil)
	include, exclude, err := machine.RequestedNetworks()
	c.Assert(err, gc.IsNil)
	c.Assert(include, jc.DeepEquals, expectInclude)
	c.Assert(exclude, jc.DeepEquals, expectExclude)
}

func joinedRelationTags(unit *state.Unit) ([]string, error) {
	relations, err := unit.JoinedRelations()
	if err != nil {
		return nil, err
	}
	tags := make([]string, len(relations))
	for i, relation := range relations {
		tags[i] = relation.Tag()
	}
	return tags, nil
}

func (u *UniterAPI) destroySubordinates(principal *state.Unit) error {
	subordinates := principal.SubordinateNames()
	for _, subName := range subordinates {
		unit, err := u.getUnit(names.UnitTag(subName))
		if err != nil {
			return err
		}
		if err = unit.Destroy(); err != nil {
			return err
		}
	}
	return nil
}

// matchUnit attempts to match a state.Unit to one of
// a set of patterns, taking into account subordinate
// relationships.
func (m unitMatcher) matchUnit(u *state.Unit) bool {
	if m.matchesAny() {
		return true
	}

	// Keep the unit if:
	//  (a) its name matches a pattern, or
	//  (b) it's a principal and one of its subordinates matches, or
	//  (c) it's a subordinate and its principal matches.
	//
	// Note: do *not* include a second subordinate if the principal is
	// only matched on account of a first subordinate matching.
	if m.matchString(u.Name()) {
		return true
	}
	if u.IsPrincipal() {
		for _, s := range u.SubordinateNames() {
			if m.matchString(s) {
				return true
			}
		}
		return false
	}
	principal, valid := u.PrincipalName()
	if !valid {
		panic("PrincipalName failed for subordinate unit")
	}
	return m.matchString(principal)
}

func newUnitToolWaiter(u *state.Unit) *toolsWaiter {
	w := u.Watch()
	waiter := &toolsWaiter{
		changes: make(chan struct{}, 1),
		watcher: w,
		tooler:  u,
	}
	go func() {
		for _ = range w.Changes() {
			waiter.changes <- struct{}{}
		}
		close(waiter.changes)
	}()
	return waiter
}

// OpenedPorts returns the list of opened ports for each given unit.
func (f *FirewallerAPI) OpenedPorts(args params.Entities) (params.PortsResults, error) {
	result := params.PortsResults{
		Results: make([]params.PortsResult, len(args.Entities)),
	}
	canAccess, err := f.accessUnit()
	if err != nil {
		return params.PortsResults{}, err
	}
	for i, entity := range args.Entities {
		var unit *state.Unit
		unit, err = f.getUnit(canAccess, entity.Tag)
		if err == nil {
			result.Results[i].Ports = unit.OpenedPorts()
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}

func (u *UniterAPI) prepareRelationResult(rel *state.Relation, unit *state.Unit) (params.RelationResult, error) {
	nothing := params.RelationResult{}
	ep, err := rel.Endpoint(unit.ServiceName())
	if err != nil {
		// An error here means the unit's service is not part of the
		// relation.
		return nothing, err
	}
	return params.RelationResult{
		Id:   rel.Id(),
		Key:  rel.String(),
		Life: params.Life(rel.Life().String()),
		Endpoint: params.Endpoint{
			ServiceName: ep.ServiceName,
			Relation:    ep.Relation,
		},
	}, nil
}

func (s *UnitSuite) setAssignedMachineAddresses(c *gc.C, u *state.Unit) {
	err := u.AssignToNewMachine()
	c.Assert(err, gc.IsNil)
	mid, err := u.AssignedMachineId()
	c.Assert(err, gc.IsNil)
	machine, err := s.State.Machine(mid)
	c.Assert(err, gc.IsNil)
	err = machine.SetProvisioned("i-exist", "fake_nonce", nil)
	c.Assert(err, gc.IsNil)
	err = machine.SetAddresses(instance.Address{
		Type:         instance.Ipv4Address,
		NetworkScope: instance.NetworkCloudLocal,
		Value:        "private.address.example.com",
	}, instance.Address{
		Type:         instance.Ipv4Address,
		NetworkScope: instance.NetworkPublic,
		Value:        "public.address.example.com",
	})
	c.Assert(err, gc.IsNil)
}

// Resolved returns the current resolved setting for each given unit.
func (u *UniterAPI) Resolved(args params.Entities) (params.ResolvedModeResults, error) {
	result := params.ResolvedModeResults{
		Results: make([]params.ResolvedModeResult, len(args.Entities)),
	}
	canAccess, err := u.accessUnit()
	if err != nil {
		return params.ResolvedModeResults{}, err
	}
	for i, entity := range args.Entities {
		err := common.ErrPerm
		if canAccess(entity.Tag) {
			var unit *state.Unit
			unit, err = u.getUnit(entity.Tag)
			if err == nil {
				result.Results[i].Mode = params.ResolvedMode(unit.Resolved())
			}
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}

// ClosePort sets the policy of the port with protocol and number to
// be closed, for all given units.
func (u *UniterAPI) ClosePort(args params.EntitiesPorts) (params.ErrorResults, error) {
	result := params.ErrorResults{
		Results: make([]params.ErrorResult, len(args.Entities)),
	}
	canAccess, err := u.accessUnit()
	if err != nil {
		return params.ErrorResults{}, err
	}
	for i, entity := range args.Entities {
		err := common.ErrPerm
		if canAccess(entity.Tag) {
			var unit *state.Unit
			unit, err = u.getUnit(entity.Tag)
			if err == nil {
				err = unit.ClosePort(entity.Protocol, entity.Port)
			}
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}

// GetAssignedMachine returns the assigned machine tag (if any) for
// each given unit.
func (f *FirewallerAPI) GetAssignedMachine(args params.Entities) (params.StringResults, error) {
	result := params.StringResults{
		Results: make([]params.StringResult, len(args.Entities)),
	}
	canAccess, err := f.accessUnit()
	if err != nil {
		return params.StringResults{}, err
	}
	for i, entity := range args.Entities {
		var unit *state.Unit
		unit, err = f.getUnit(canAccess, entity.Tag)
		if err == nil {
			var machineId string
			machineId, err = unit.AssignedMachineId()
			if err == nil {
				result.Results[i].Result = names.MachineTag(machineId)
			}
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}

// HasSubordinates returns the whether each given unit has any subordinates.
func (u *UniterAPI) HasSubordinates(args params.Entities) (params.BoolResults, error) {
	result := params.BoolResults{
		Results: make([]params.BoolResult, len(args.Entities)),
	}
	canAccess, err := u.accessUnit()
	if err != nil {
		return params.BoolResults{}, err
	}
	for i, entity := range args.Entities {
		err := common.ErrPerm
		if canAccess(entity.Tag) {
			var unit *state.Unit
			unit, err = u.getUnit(entity.Tag)
			if err == nil {
				subordinates := unit.SubordinateNames()
				result.Results[i].Result = len(subordinates) > 0
			}
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}